Measles virus RNA investigation in peripheral whole blood specimens collected from subacute sclerosing panencephalitis patients by real-time PCR method

Subacute Sclerosing Panencephalitis (SSPE) disease is an infection resulted from a virus which undergoes mutation during measles infection and is transferred to the brain in its dormant form. It can turn into its active form after many years and leads to irreversible damages in CNS and followed by death. Studies performed with real-time PCR method in diagnosis of SSPE is generally based on using brain biopsy materials for investigation measles virus (MV) RNA considering its being most reliable and frequently positive material. However, that positive results were found in a study carried out with blood samples of SSPE patient, shed a light on using blood material, which is easier to obtain, as a target material instead of brain material. In this study, measles vaccine and cell cultured measles strain from a patient were used as positive controls and whole blood specimens of six healthy donors provided from Yeditepe University Hospital were used as negative controls. Since it is determined that RNA encoded by N (nucleoprotein) gene belonging to the genome of the measles virus causing SSPE is the most abundant transcript, it was aimed to amplify N gene of MV-RNA. In this study we succeeded to obtain a positive result in a SSPE patient blood sample. However, no N RNA detection could be achieved in rest of the other patient blood samples. As conclusion, real-time PCR method validation we performed was confirmed with one positive result. Nevertheless, development of more comprehensive multiplex real-time PCR methods using internal control and additionally further detailed molecular analysis by sequencing will be required to obtain more accurate and conclusive results in diagnosis of SSPE.